Grey Hair: A New Question

So, I have a twist on the usual buzz about "grey" hair. People usually direct their questions towards finding out how to stop it. My question is if there is any way to cause it, maybe not in total isolation but without affect stem cells and such.

With the huge amount of drugs and their side effects we have now, I would expect some would cause premature greying. However, my searches have led to no findings (due to the immense clutter of information on stopping it).

A few years ago I suffered a serious illness and afterwards my hair started going grey much faster than it had previously. I can't say for certain that it was the illness that caused it, but it was quite a coincidence if not.

I just found this at http://en.allexperts.com/q/Genetics-1795/hair-turn-grey-1.htm [Links inactive - To make links active and clickable, login or click here to register]

Normal hair follicles contain stem cells and stem-cell derivatives (melanocytes) that produce the hair proteins (keratins) and the pigments (melanins) that are deposited within the hair fibers. Hair is hollow like a tube, and the pigment is deposited within the tube as the newly formed keratin fibers weave and make the hair shaft. As long as the hair follicle is healthy, it keeps producing new keratin fiber and new pigment; in fact, as you grow and age, many hairs fall out and new hairs are grown. However, when the body is sick in some way, hair production slows in order for the body to conserve proteins for more important uses, such as forming a strong immune response against infection with protein antibodies. In addition to keratin fiber production slowing, the hair follicles stop making pigment. So, after a while of illness or stress, the overall appearance of the hair is pigmentless, or gray or white (depending on the natural color of your keratin strands). So, gray hair is due to the absence of pigment. Furthermore, people under extreme stress or illness can become gray "overnight" because the body sort of harvests all of the pigment from the hair (our bodies cannot break down keratin, though). This is why gray hair strands are usually all gray, and not just the part that has grown since the cell stopped producing pigment (it's not just that you didn't catch it when it was shorter). This is a process similar to when trees change colors in the fall-- chlorophyll is harvested from the leaves and the different colors of red, yellow, orange, and brown are what is left after the chlorophyll is removed, similar to our gray/white hair.

Graying associated with aging is similar to stress/illness graying, however, it is usually due to the stem cells in the hair follicles dying. This also causes thinning of the hair, or even baldness. Some people only gray and never lose hair, and this may be an intermediate phenotype in which the cells are surviving, but not at optimal capacity for protein production: the cells are conserving energy and protein to stay alive. In addition, the melanocytes (derived from the stem cells) that are directly resposible for melanin production may die, leaving the stem cells intact to produce keratin. The hair shaft itself protects the follicle from other damage so this function is conserved; however, the pigment has less protective function so it is expendable.

Premature graying is probably a phenotype based on survival of the stem cells in the hair follicles. In addition, there could be a deficiency in melanin production by the melanocytes that is not expressed until adulthood. There is not a lot of research in this area, because there are no medically important consequences.